Messages in this thread | | On 21/06/17 22:56, David Miller wrote:
> From: Michael D <michael.j.dilmore@gmail.com> > Date: Wed, 21 Jun 2017 22:41:07 +0100 > >> I don't think you can stop it being dereferenced... you just need to >> prevent an attacker from exploiting the null pointer dereference >> vulnerability right? And this is done by returning the function right >> away? > What's all of this about an "attacker"? > > If there is a bug, we dererence a NULL pointer, and we should > fix that bug. > > The BUG_ON() helps us see where the problem is while at the > same time stopping the kernel before the NULL deref happens. Ok this is starting to make sense now - went a bit off track but think my general thinking is ok - i.e. if we return the function with an error code before the dereference then this basically does the same thing as BUG_ON but without crashing the kernel.
Something like:
if (WARN_ON(!new_active_slave) { netdev_dbg("Can't add new active slave - pointer null"); return ERROR_CODE }
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